The present invention relates to removal of deposits from the inner surfaces of polymer processing machinery.
Resin deposits can accumulate on the internal surfaces of resin processing machinery. It is sometimes desirable to purge these deposits from the internal surfaces. Purging agents are used for this purpose and generally act via chemical and/or abrasive action.
The present invention provides a composition for purging resin deposits from the inner surfaces of polymer processing machinery upon the flow of a stream of resin through the polymer processing machinery. The composition includes a mixture of purging agents separate from the resin in a state pourable into the stream of resin as an additive. The purging agents include a blowing agent effective to induce foaming of the stream of resin, and an abrasive effective to scrub the resin deposits from the inner surfaces of the polymer processing machinery. The purging agents further include a surfactant effective to promote the flow of the stream of resin along the inner surfaces of the polymer processing machinery. A binder binds the purging agents together in the mixture.
The present invention also provides a method for purging resin deposits from the inner surfaces of polymer processing machinery. The method includes feeding a mixture comprised of a blowing agent, an abrasive, a surfactant, and a binder into the stream of resin in the polymer processing equipment.